The conventional zipper fastener used in a variety of clothing articles and other products has evolved into a number of fastener systems. One line of development is exemplified by U.S. Pat. Nos. 3,990,130, 4,308,644, 4,275,467, and 3,924,305 in which air or water tighteness had been the objective. Extra flaps of material are used many times to obtain such a fluid tight seal. Others have used the extra flaps in a more aesthetic manner, such as to conceal the zipper teeth and slide mechanism. In addition, these extra flaps can be used for protective means. Boots, jackets, gloves, pants, etc. employ these various ideas to protect an inner environment (e.g., a person's body) from the external elements.
Another development of the basic zipper concept is set forth in U.S. Pat. No. 2,229,216, where a pair of slides are joined into a component to allow for a double-sealing mechanism of extra strength and durability. This type of double slide component has been employed in articles that use a removable interior liner of some sort, or that require extra strength in the fastener system.
This invention relates to joining and separating pairs of fasteners in a simplified manner, for example to open and close passages between separate items or volumes. Many products have need to attain this versatility, of which sleeping bags, tents, or other devices having one or more flexible wall or panel members, are typical examples. Consumers may purchase sleeping bags individually only to discover later the separate bags cannot be connected since the zippers are incompatible. As a solution, compatible zippers have been used so that one may join a pair of bags together, thus doubling the contained sleeping space, or one may retain the sleeping bags as separate members. Similarly, one might create a larger tent by attaching an addition to the original tent. Once again zippers or other compatible connectors can be used to achieve this objective.